I. Field of the Invention
As used herein, the term "battery" refers to an electrochemical storage device that may consist of one or more chemical power "cells" that each store electrical energy in the form of chemicals contained within the device. Typically, each cell includes three principal parts, including a positive electrode, a negative electrode and an electrolyte. The electrolyte is normally a liquid material, usually a relatively large molecule, that tends to dissociate or break-up into both positive and negative fragments. The positive electrode is composed of a material that naturally reacts with the positive fragment of the electrolyte, and requires free electrons for the reaction to proceed. On the other hand, the negative electrode is a material that naturally reacts with the negative fragment, and so, must rid itself of extra electrons as the chemical reaction proceeds. In this manner, each of the positive and negative electrodes have an electron surplus or deficiency which gives rise to a voltage, or difference in charge, between the two electrodes.
Batteries are typically made using one of several conventional battery structures, which are generally either "monopolar" or "bipolar." The most common batteries are monopolar batteries, for example, a conventional, 12-volt lead-acid car battery. These batteries have six 2-volt cells that each use lead (Pb) as the active material in one (i.e., the positive) electrode, lead-dioxide (PbO.sub.2) as the other active material in the other electrode, and sulfuric acid (H.sub.2 SO.sub.4) as the electrolyte. Typically, monopolar configurations are useful for low-voltage applications, or where other factors, such as high-longevity, are paramount, but they are generally not well suited for high-voltage applications. For these applications, other conventional battery structures such as bipolar configurations are generally better suited.
Distinguishing features of these various conventional battery structures will be discussed below.